<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>我的页面</title></head>
<body>
<h1 id="alert"></h1>
<script>
    var al = document.getElementById('alert');
    for (var i = 0; i < 100; i++) {

    }
</script>
</body>
</html>